The invention relates to an ultrasound test apparatus for elongated test specimens that are constant throughout their length, in particular pipes and rods that are transported longitudinally along a test line and thereby pass through a test machine that is arranged on the test line.
So called whole body test installations are used as test machines for test specimens having a round, outer cross section or a regular, polygonal profile, the test specimens are scanned along a helical path with ultrasound. The test specimens are moved along the test line relative to the test machine. Either the test specimens are themselves additionally rotated around their longitudinal axis with the test machine remaining fixed, or the test machine has a rotor which turns around the axis of the test specimen, that is, the test line. Such test installations are, for example, described in J and H Krautkramer, "Ultrasonic Testing of Materials," 4th revised edition, Translation of 5th German Edition, Springer Verlag, pages 442 to 461.
However, other longitudinal profiles may be considered as test specimens, for example fin wing pipes, train tracks, ingots, special profiles or the like. With such test specimens helical scanning, in general, is not possible. Ultrasound testing is thus carried out through multiple, locally fixed test heads on a test machine. The test heads are arranged along the outer contour of the profile such that the necessary, user selected tests can be run.
Ultrasound test devices of the type mentioned above are, as a rule, adjusted by the manufacturer of the test pieces, in conjunction with production. The ultrasound test should, however, on the one hand yield the maximal possible result with respect to the quality of the individual test specimens but, on the other hand, not delay production or make it more difficult.
During production a certain tonnage of test specimens with a pregiven cross section form are typically produced first, and then a second type of profile form is processed, etc. In order to carry out such a change in profile an ultrasound test device must be adapted relatively rapidly, in any case quickly enough so that production of the profiled parts is not delayed. Accordingly, there have been attempts to make the ultrasound test apparatus change over quickly from one profile form to another profile form. These solutions, however, have not kept pace with modern developments in production.